I've followed up to an earlier mailing list discussion to file a PR that
extends the IPv6 nameserver blacklist behaviour to all OSes, not just
Windows. Details are in the description there.
https://github.com/c-ares/c-ares/pull/193
As suggested in the contribution guidelines, I'm echoing this fact on
the mailing list.
-- Brad SpencerReceived on 2018-05-17